The chief objective of these studies is the development of therapeutic methods and agents which will achieve significant prolongation of life for patients with acute leukemias, chronic leukemias and other forms of disseminated malignant disease. Ancillary objectives are the acquisition of knowledge about the natural history of these disorders and the development of clinical pharmacological principles which may have wider application. The major method by which these objectives are attained is by carefully controlled patient studies in collaboration with other members of Acute Leukemia Cooperative Group B.